As is known, recent biological, microbiological and pharmacological applications involve introducing molecules into cells, which is done by inserting the molecules through cell membranes.
The molecules may be inorganic substances (e.g., drugs) or organic molecules (cells are known to be inserted, for example, with DNA molecules).
Molecules are introduced using various methods, including:
viral vectoring: associating the molecule with a virus, which is then introduced into the cell;
chemical vectoring: associating the molecule with a chemical substance for reducing the resistance of the cell membrane and so permitting introduction of the molecule into the cell; and
ballistic methods: accelerating the molecule so that it strikes and penetrates the cell membrane.
Known methods involve several drawbacks, including: risk of immunity reaction to the vector; production difficulties and poor stability of the vector itself (viral vectoring); ineffectiveness, toxicity and poor selectivity (chemical vectoring). As for ballistic methods, these only apply to surface cells.
New so-called electroporation methods have recently been devised, which provide for briefly applying a strong electric field to the cells to permeabilize, and so enable substances to penetrate, the cell membrane.
One problem posed by known electroporation methods is establishing the value of the electric field applied, which must be high enough to permeabilize the cell membrane, but not so high as to cause irreversible damage to the cell.
More specifically, known electroporation devices and methods employ a fixed output voltage value (determined, for example, experimentally), so that, in certain operating conditions, the electric field may be too low, thus preventing introduction of the substances, and/or too high, thus resulting in irreversible damage to the cell.